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Comparison · Comms
Roundcube vs Slack
A side-by-side editorial comparison of Roundcube and Slack — release velocity, themes, recent moves, and the top alternatives to consider.
Roundcube vs Slack: at a glance
What is Roundcube?
Roundcube patches 28+ vulnerabilities across two branches in a five-month hardening sprint
Roundcube has shipped six security releases across its main 1.7.x and LTS 1.6.x branches since June, patching a cumulative 28+ vulnerabilities including an RCE via the markasjunk plugin's cmd_learn driver, IMAP command injection through LITERAL+ byte-count desynchronization, multiple SSRF bypasses, cross-user contact group access, and zero-click stored XSS. The simultaneous dual-branch cadence shows active maintenance of both lines.
What is Slack?
Slack raises the Marketplace bar back to ten installs while the agent platform consolidates.
Slack's developer platform runs two tracks. The agent build-out has produced a spark roughly every two weeks since June — MCP client, a skills plugin targeting Claude Code and Cursor, and Slack Code — and now has a consolidation date attached: assistant_view is deprecated in February 2027, replaced by an Agent Sessions API. The second track is platform administration and tooling, and this window belongs to it: Marketplace submissions again require at least ten installed active workspaces, held throughout the review, after a period at a lower temporary threshold. The CLI has shipped three times since late July.
Roundcube vs Slack: editorial side-by-side
Roundcube
5.0COMMS
Roundcube patches 28+ vulnerabilities across two branches in a five-month hardening sprint
◆ Current state
Roundcube has shipped six security releases across its main 1.7.x and LTS 1.6.x branches since June, patching a cumulative 28+ vulnerabilities including an RCE via the markasjunk plugin's cmd_learn driver, IMAP command injection through LITERAL+ byte-count desynchronization, multiple SSRF bypasses, cross-user contact group access, and zero-click stored XSS. The simultaneous dual-branch cadence shows active maintenance of both lines.
◆ Where it's heading
The volume and variety of external security reports — from Horizon3.ai, Samsung R&D, pwn.ai, and independent researchers — indicates Roundcube's attack surface is under sustained scrutiny. The 1.7.0 release in May introduced meaningful features (Markdown rendering, improved OAuth2/OIDC, mandatory public_html entry point), but the months since have been consumed by patching. Feature development on 1.7.x appears paused until the security debt settles.
◆ Prediction
Another paired security release across 1.7.x and 1.6.x is likely within 6-8 weeks given the cadence. The SSRF and CSS parsing issues have required multiple iterations to close fully, suggesting the hardening work isn't finished.
Slack
6.3COMMSCOLLAB
Slack raises the Marketplace bar back to ten installs while the agent platform consolidates.
◆ Current state
Slack's developer platform runs two tracks. The agent build-out has produced a spark roughly every two weeks since June — MCP client, a skills plugin targeting Claude Code and Cursor, and Slack Code — and now has a consolidation date attached: assistant_view is deprecated in February 2027, replaced by an Agent Sessions API. The second track is platform administration and tooling, and this window belongs to it: Marketplace submissions again require at least ten installed active workspaces, held throughout the review, after a period at a lower temporary threshold. The CLI has shipped three times since late July.
◆ Where it's heading
The install requirement moving back up is a distribution decision arriving in the middle of a platform push, and the two point the same way. Slack is making it easier to build agents and harder to list one, which favours developers who already have distribution — existing workspace tools and vendors — over a new app hoping the Marketplace supplies its first users. Combined with the assistant deprecation and the Agent Sessions API, the platform is narrowing on one agent surface and one class of builder rather than widening the funnel.
◆ Prediction
The threshold is described as a return from a temporary lower bar rather than a new policy, so the open question is what replaces the Marketplace as the discovery path for an app that cannot reach ten workspaces on its own. These entries do not answer it.
Alternatives to Roundcube and Slack
Other Comms products tracked by Sparkpulse, ranked by recent ship velocity. Each card links to a full editorial trajectory and lets you pivot into a head-to-head comparison with either Roundcube or Slack.
Element
Element 1.12.33 ships: simpler recovery keys, mandatory verification, no libolm migration.
Tawk.to
tawk.to's widget 4.4.0 turns to keyboard and screen-reader fixes after a run of form work.
Krisp
Krisp 2.83.4 brings Voice Translation into conference calls and lightens Accent Conversion.
Pixelfed
Pixelfed 0.15.2 ships the PHP RCE patches and turns cached timelines on for everyone.
Salesmsg
Salesmsg Reviews can now trigger follow-ups automatically based on a customer's latest rating.
See all Roundcube alternatives → · See all Slack alternatives →
Recent activity from Roundcube and Slack
Latest ship moves from both products, interleaved chronologically. ⚡ = editorial spark.
- 1mo agoRoundcubeRoundcube Webmail 1.7.4
- 1mo agoRoundcubeRoundcube Webmail 1.6.19
- 1mo agoSlackUpdated installation requirement for Slack Marketplace apps
- 1mo agoSlackCLI adds app-approval status checks and custom app icons
- 2mo agoSlackAnnouncing Slack Code ⚡
- 2mo agoSlackAgent Sessions API replaces assistant_view, deprecated Feb 2027
- 2mo agoRoundcubeRoundcube Webmail 1.7.3
- 2mo agoRoundcubeRoundcube Webmail 1.6.18
- 3mo agoSlackAnnouncing the Slack MCP and Skills Plugin ⚡
- 3mo agoSlackCLI adds manifest diff and a Block Kit preview command
- 3mo agoRoundcubeRoundcube Webmail 1.6.17
- 3mo agoRoundcubeRoundcube Webmail 1.7.2
Frequently asked questions
What is the difference between Roundcube and Slack?
They serve adjacent needs but don't currently overlap on shipped themes. Slack is currently shipping more aggressively (velocity 6.3 vs 5.0), with 0 editorial sparks in the last 30 days against 0. See the at-a-glance table above for a side-by-side breakdown of velocity, recent sparks, and editorial themes.
Is Roundcube better than Slack?
Sparkpulse doesn't pick a winner — we score release velocity, not feature parity. Slack is currently shipping more aggressively (velocity 6.3 vs 5.0), with 0 editorial sparks in the last 30 days against 0. For your specific use case, the alternatives sections above list other Comms products to evaluate alongside.
What are the best alternatives to Roundcube?
Top Roundcube alternatives in Comms are ranked by recent ship velocity. Browse the "Roundcube alternatives" section above for the current picks, or visit /alternatives/roundcube for the full list with editorial commentary on each.
What are the best alternatives to Slack?
Top Slack alternatives in Comms are ranked by recent ship velocity. Browse the "Slack alternatives" section above for the current picks, or visit /alternatives/slack for the full list with editorial commentary on each.